ACS724: Automotive-Grade, Galvanically Isolated Current Sensor IC With Common-Mode Field Rejection in a Small-Footprint SOIC8 Package

The Allegro™ ACS724 current sensor IC is an economical and
precise solution for AC or DC current sensing in industrial,
automotive, commercial, and communications systems. The
small package is ideal for space-constrained applications
while also saving costs due to reduced board area. Typical
applications include motor control, load detection and
management, switched-mode power supplies, and overcurrent
fault protection.

The device consists of a precise, low-offset, linear Hall
sensor circuit with a copper conduction path located near the
surface of the die. Applied current flowing through this copper
conduction path generates a magnetic field which is sensed
by the integrated Hall IC and converted into a proportional
voltage. The current is sensed differentially in order to reject
common-mode fields, improving accuracy in magnetically
noisy environments. The inherent device accuracy is optimized
through the close proximity of the magnetic field to the Hall
transducer. A precise, proportional voltage is provided by the
low-offset, chopper-stabilized BiCMOS Hall IC, which is
programmed for accuracy after packaging. The output of the
device has a positive slope when an increasing current flows
through the primary copper conduction path (from pins 1 and
2, to pins 3 and 4), which is the path used for current sensing.
The internal resistance of this conductive path is 1.2 mΩ typical,
providing low power loss.

The terminals of the conductive path are electrically isolated
from the sensor leads (pins 5 through 8). This allows the
ACS724 current sensor IC to be used in high-side current sense
applications without the use of high-side differential amplifiers
or other costly isolation techniques.

The ACS724 is provided in a small, low-profile surface-mount SOIC8
package. The leadframe is plated with 100% matte tin, which is
compatible with standard lead (Pb) free printed circuit board assembly
processes. Internally, the device is Pb-free, except for flip-chip high-temperature
Pb-based solder balls, currently exempt from RoHS.
The device is fully calibrated prior to shipment from the factory.

Design Support Tools

Allegro MicroSystems, LLC provides Gerber files for reference only. Any material, information, or instructions are provided AS IS without warranty of any kind. It is the responsibility of the User(s) to optimize any Printed Circuit Board (PCB) layout, as well as the selection of any components, for the specific application of the User(s).

Allegro’s products are not to be used in any devices or systems, including but not limited to life support devices or systems, in which a failure of Allegro’s product can reasonably be expected to cause bodily harm.